1. Field of the Invention
The present embodiment relates to a light emitting device, a light emitting device package and a lighting apparatus.
2. Description of the Related Art
Group III-V nitride semiconductors are focus of attention as light emitting devices, such as light emitting diodes (LEDs) or laser diodes (LDs) due to physical and chemical characteristics thereof. Nitride-based light emitting devices generate light using an energy bandgap of an active layer located between an N-type GaN semiconductor layer and a P-type GaN semiconductor layer. Now, nitride-based light emitting devices generating light having wavelengths corresponding to green, red and blue colors are being utilized to emit white light using properly selected phosphors.
The application range of light emitting devices is being changed from conventional mobile apparatuses to TVs, backlight units (BLUs) for MNTs and general lighting apparatuses. In order to apply light emitting devices to TVs, MNTs and general lighting apparatuses, ESD tolerance of a designated level, generally ESD tolerance of a level of −2 KV, is required.
ESD means electrostatic discharge of several thousands of volts or more generally generated when an electronic apparatus contacts a charged object, and may damage power supply devices to provide power to light emitting devices and various other electronic apparatuses as well as the light emitting devices.
In general, nitride-based light emitting devices cannot have ESD tolerate of a level of −2 KV. Therefore, in case that a light emitting device is applied to an apparatus, such as a backlight unit, a Zener diode is added to one side of a light emitting device package, thus allowing the light emitting device to have ESD tolerance by means of the Zener diode.
However, when the Zener diode is added to the light emitting device package so as to allow the nitride-based light emitting device to have ESD tolerance, the Zener diode is located adjacent to the light emitting device in the package and thus influences brightness of the light emitting device. Further, if the surface of the Zener diode is formed in black, the Zener diode serves as a black body and thus absorbs a portion of light emitted from the light emitting device, thereby reducing brightness of the light emitting device. In addition, the Zener diode is received in the package, thereby increasing manufacturing costs of the overall package.